North Korean leader Kim Jong-un gives field guidance at a new tree nursery run by the military in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang May 29, 2015. Photo: Reuters/KCNA

A drought in North Korea could lead to huge food shortages this year, the top U.N. official in the country told Reuters in an interview.

Rainfall in 2014, the lowest in records going back 30 years, was 40-60 percent below 2013 levels, and reservoirs are very low, said Ghulam Isaczai, the U.N. resident coordinator.

"We're extremely concerned with the impact of drought which will affect the crop this year severely. And we might be faced with another major incident of food availability or even hunger," said Isaczai. "It is going to create a huge deficit between the needs and what is available."

If El Nino weather conditions bring more drought this year, the situation in 2016 could be even worse, he warned.

"This is currently the rice-planting season. Normally they submerge the land almost a week or two in advance. But this year, I've seen it myself - they're doing it in the dry, actually planting rice. So what we're hearing right now is that they're switching to maize and corn because that requires less water."

Some farmers, already struggling with a shortage of fuel and equipment, have resorted to using buckets to water seedlings, he said. The effect of North Korea's lack of agricultural infrastructure such as irrigation systems was visible on the border, where "dry and harsh" North Korean land met green fields in China.

A famine in the 1990s killed as many as 1 million North Koreans but recently many international donors have been reluctant to help because of Pyongyang's restrictions on humanitarian workers and international concerns over its nuclear ambitions.

"Let's not make aid political," Isaczai said.

Electricity hit

The United Nations provides nutritional supplements to schools and hospitals but does not have the funds to supply rice for North Korea's 24.6 million population, 70 percent of whom are already classed as "food insecure".

"How are they going to fill this gap? I think they have reached out to some countries - to India, to China, to Russia," Isaczai said.

The lack of water has dried up rivers and streams and has also hit electricity supply, which was at its worst in winter when hydroelectric power was restricted to reserve water for the rice-planting season.

"What the government confirmed to me is that they're operating at 50 percent of capacity in terms of power generation. A lot of it is now related to water," the U.N. official added.

Blackouts in Pyongyang last anything from 8-9 hours to a whole 24 hours and many hospitals are unable to operate.

Isaczai said he thought the food situation would not be as bad as in previous major droughts, since communities were now more resilient and might have some reserves.

New farming rules - which allow smaller, family-sized teams to run farms - meant more efficiency and ownership, he said, with families allowed to keep livestock and farmers able to keep surplus crops.

"Also there are small markets emerging in rural areas, like kind of farmers' markets where people can barter or trade or sell things."

Some people were also selling food on the street, which might be a few eggs or apples, enabling families to supplement the food they get from the national ration system.

The reforms may not be fast or widespread, Isaczai said, and the impact may take three to five years to be felt.

The government also set a target last year of building 20,000 greenhouses, he said, which would make more vegetables available and diversify diets, but the country needs help to build them.